Synthesis of Homochiral Camphor Annulated Pyrrole Derivatives
N. Sewald, V. Wendisch,
Two new derivatives of camphor annulated to pyrrole have been synthesized representing potentially useful mono- and bidentate chiral ligands. A new method for the cleavage of the NN bond in 1-(dimethylamino)pyrroles is described.
Enantioselective copper(I) catalyzed 1,4-addition of diethylzinc to cyclohexenone: asymmetric induction as an unexpected source of structural information
V. Wendisch, N. Sewald,
The conjugate addition of diethylzinc to cyclohexenone in the
presence of catalytic amounts of homochiral sulfonamides and
different copper(I) salts has been examined. The anion of the
copper(I) salt significantly influences the topicity of the
1,4-addition. With the same absolute configuration of the chiral
catalyst, CuCN favours fomation of R-3-ethylcyclohexanone, while the
S-configured product predominates for all other copper(I) salts
used. This clearly hints towards structural differences between the
catalytically active complexes.